ref: f86a95697db4370ac5fc12432aa20117d0754139
dir: /lib/bio/test/bio-peek.myr/
use std use bio const main = { var f /* Must be bigger than a bio buffer (ie, > 64k) */ var buf : byte[64*1024] match bio.open("data/datafile", bio.Rd) | `std.Ok bio: f = bio | `std.Err m: std.fatal("Unable to open data file: {}\n", m) ;; std.assert(peekb(f) == 0x30, "wrong byte value read from datafile\n") std.assert(peekc(f) == '0', "wrong char value read from datafile\n") bio.read(f, buf[:4]) /* skip ahead 4 bytes */ std.assert(peekb(f) == 0x34, "wrong byte value read from datafile\n") std.assert(peekc(f) == '4', "wrong char value read from datafile\n") bio.read(f, buf[:]) /* skip ahead 64k */ std.assert(peekb(f) == 0x30, "wrong byte value read from datafile\n") std.assert(peekc(f) == '0', "wrong char value read from datafile\n") bio.close(f); std.put("Succeded peeeking values\n") } const peekc = {f match bio.peekc(f) | `std.Ok c: -> c | `std.Err `bio.Eof: std.put("eof\n") -> -1 | `std.Err e: std.fatal("error reading\n") -> -1 ;; } const peekb = {f match bio.peekb(f) | `std.Ok b: -> b | `std.Err `bio.Eof: std.put("eof\n") -> -1 | `std.Err e: std.fatal("error reading\n") -> -1 ;; }